Board Thread:Pokémon Help/@comment-68.196.90.225-20151230062224/@comment-31433193-20151230133226

There is always a small chance that a random Egg will obtain a Hidden Ability. In conclusion, just keep hatching more eggs till you find one :)

PS: Same thing with obtaining Shinies.

Hope this can help you :)

~The Crimson Pumpkin